For most home users, I’d have absolutely no problem recommending a Symple PC. It’s $89, it comes with a warranty, and Unity is simple enough that either your grandson or grandmother can figure out how to use it. And if Ubuntu’s not your thing: wipe it and put the distro of your choice on it. It’s true that if you open the case to add more hardware you void your warranty, but so what? It’s only $89, which won’t get you into some rock concerts these days.